Device for giving angular motion when shifting jaw clutches



4 R R CROOKSTON ETAL 2,668,450

. DEvIE FOR GIVING ANGULAR MOTION WHEN SHIFTING JAW CLUTCHES lled Nov. 1. 1950 2 Sheets-Sheet 1 DRAW-WORKS ASSEMBLY C FIG. r --1 GOIPOUND UNIT rum: uovER NUDGER ASSEMBLY AIR SUPPLY AIR SUPPLY FIG. 3.

INVENTORS. Robert R. Crooks fon,

BY Arthur L%/ A T TORNEY,

' Feb. 9, 1954 R R iled NOV. 1, 1950 CROOKSTON ETAL 2,668,450 DEVICE FOR GIVING ANGULAR MOTION WHEN SHIFTING JAW CLUTCHES 2 Sheets-Sheet 2 FIG. 2.

INVENTORS. Robert R. Crooksfon, Arthur L. Seljos,

BY m W A TTORNEY.

Patented Feb. 9, 1954 UNITED STATES PATENT 'OFFI CE 2,668,450 DEVICE FOR GIVING ANGULAB MOTION WHEN SHIFTING J AW CLUTGHES Robert R. Grookston and Arthur L. Scljos, Houston, Tex., assignors,

by mesne assignments, to

Standard Oil Development Company, Elizabeth, N. J, a corporation of Delaware Application November 1, 1950-, Serial No. 193,462

1 Claim. 1

- giving one jaw of a disengaged jaw clutch limited angular motion to assist in the proper engagement of the clutch when the two jaws are brought into contact.

In somema'chinery installations jaw clutches are usedin the mechanical train which transmits power from the prime mover to the working tool. In order to allow the jaw clutches to be engaged without undue punishment, it is desirable that a small force give one of the jaws a relatively slow arcuate movement with respect to the other as the jaws are brought into engagement. If the prime mover used to transmit the power in installation has a minimum speed, it is not possible to use itfor this purpose and thus it is necessary either touse; the prime mover with its necessarily high rotative speeds for turning one of the jaws which is unsatisfactory in causing the punishment of the jaw elements or else to have the operation performed manually.

The present application is directed to a device forgiving one jawof a clutch limited movement with respect to the other jaw of a disengaged clutch in order to allow the smooth engagement of the clutch. Other advantages and objects of the present invention may be seen from the following description taken with the drawing in which I l is a view partly in section showing an illustrative view of a rotary drilling rig;

Fig. 2 is an enlarged view partly in section of a. portion of the device of Fig. 1 showing details 7 of construction of an embodiment of the apparatus of the present. invention; and

Fig. 3 is a diagrammatic view taken along line 3-3 of Fig. 2 showing the control mechanisms for the device of Fig. 2.

Turning now specifically to the drawing and first to Fig. 1, the power supply consists of a prime mover A which may be for example a diesel engine. It is connected through a suitable drive shaft ii to a compound unit B. The details of construction of the compound unit B are not shown except for a take-off power shaft I2 with a sprocket !3 for transmitting power to draw works assembly C. The draw works assembly is shown in somewhat simplified form with a jack shaft M, line shaft l5 and drum it mounted on a drum shaft ii. Jack shaft H! has a friction clutch l8 carrying a sprocket Id mounted on its end and arranged to receive power through drive chain as from compound unit B. Jack shaft 14 na'sfa sprocket 2i mounted thereon which transmits power to a corresponding sprocket 2Z (Cl. Tie-138) 2 mounted on the line shaft through drive chain 23. A pair of jaw clutches are mounted on line shaft [5. One pair for the low speed driveof the drum I6 consists of jaw fixed to shaft i5 and jaw 25 to be engaged or disengaged with jaw 24 and carrying a sprocket 26 which transmits power to sprocket 21 mounted on drum shaft IT by means of drive chain 28. The other jaw clutch which is the high speed drive for the drum consists of jaw ZHs'ecured to the line shaft and jaw 36 arranged to be engaged and disengaged therewith and carrying sprocket 3| which is arranged to transmit power to sprocket BZ-mounted on the drum shaft l i by means of drive chain 33.

An assembly D in accordance with the present invention is mounted for cooperation with jack shaft [4.

It is to be understood that the showing of the prime mover compound unit and draw works is for illustrative purposes only. In a heavy duty drilling rig it is customary to provide 2 or 3 internal combustion engines as the prime movers when this source of'power is used and in a draw works it is customary to have more complicated apparatus,- for example, a sand reel in addition to the drum. However, the apparatus shown illustrates the principles involved, namely, the jaw clutches are in the power train transmitting power from the prime mover to the work unit and that it is desirable t c provide a means for giving a shaft limited angular motion in order to aid in the shifting of jaw clutches in such an assembly.

The details of construction of unit D are shown in Figs. 2 and 3. A frame 39, which may be the frame of the draw works, is provided as a mounting means. A stub shaft 40 is mounted concentrio with jack shaft i l. A friction clutch assembly is provided for connecting and disconnecting shaft 46 with jack shaft M. This clutch consists of a hub M fixed to jack shaft it and a casing 42 fixed to shaft All with a compressed air operated friction unit ts fixed to casing 42 and adapted to be expanded into frictional contact with hub 4|; Compressed air for actuating the clutch is supplied through an inlet line 44 which passes through a seal 45 to axial passage 46 in shaft 46, the axial passage connecting with a radial passage 41 in casing 4i and thence through connection it to the friction unit 43.

Mounted on shaft 46. is an over-running clutch consisting of hub 513, casing 5i and bearing balls Huh 5a is secured to shaft s'tthrough key 53. Power transmitting rollers are arranged between not so and easing 5! to transmit ower from hub 50 to casing Casing 5| is secured to member 42 of the friction clutch by screws 54. Since an overrunning clutch is well known to the art, the specific details of construction of this device will not be given. It is believed sufiicient to state that when casing 54 is rotated in a clockwise direction (as when looking at the end of shaft provided with a seal at a greater speed than shaft 4!! it rotates independently of shaft 40 but when shaft 40 (carrying hub 59 with it) rotates at a greater speed in a clockwise direction than casing 51, the hub drives casing 5| through ball 52.

A sprocket B0 is mounted on shaft 40 and is fixed thereto by key 6 l. Mounted below sprocket 6D and secured to frame 39 is a power unit consisting of cylinder 52 and piston 63 with a piston rod 64 secured thereto and extending through the head end of the cylinder. A return unit consisting of cylinder 66, piston 61 and piston rod 68 secured thereto is also attached to frame 39 with piston rod 58 parallel with piston rod 54. A compressed air inlet line 59 leads into the head end of cylinder 66 of the return unit. A drive chain Hi engages with said sprocket 6B with one end secured to piston rod 64 of the power unit by means of head H and the other end connected to piston rod 68 of the return unit by head 12.

A suitable control mechanism for the device is shown in Fig. 3. Compressed air is supplied from suitable means, not shown in the drawing, to air inlet lines which, for convenience, are

all designated 15 on the drawing. For controlling the operation a valve of the bleeder type 16 controls the admission of air into two branches Ti and 18. Branch 11 leads to the diaphragm of normally closed diaphragm valve !9 which controls the admission of air through air inlet 44 to the air operated clutch. Branch 18 has a time delay unit 80 arranged therein and is connected to the diaphragm of normally closed diaphragm valve 8] which controls the admission of air to air inlet line of power unit. The return air cylinder is supplied with air continuously from air inlet line 15.

unit. Thus with the jack shaft master clutch l8 disengaged, jack shaft I4 is given angular movement by assembly D. This movement is produced simply by opening valve 16 in the air control system which allows compressed air to pass to the diaphragm of valve 19 which opens this normally closed valve so that air passes through line 44 to the clutch unit 43 which mechanically connects shaft 40 to jack shaft 64. Opening valve 16 also allows air to flow through branch 18 and through time delay unit and to the diaphragm of normally closed diaphragm valves 8| so that air can pass from air inlet line 15 through line '55 into the cylinder of the power unit. This forces the piston 63 downwardly and the movement is transmitted through piston rod 64, head II and drive chain Ill and sprocket 6|! to shaft 49 giving the shaft angular movement. As the .shaft moves either the jaw elements 24, 25 or 29, 30 may be engaged in the manner conventional to the art. As soon as the jaw elements are @1 7 gaged the master clutch [8 may be engaged and power is then transmitted from the prime mover A to the drum [6. As soon as the selected jaw clutch is engaged valve 16 may be closed and since this valve is of the bleeder type it bleeds out air from the air control lines causing valves 19 and 8| to close. Since valves 19 and BI are also of the bleeder type, they bleed out the air from the clutch unit 43 and from the power cylinder 62. This causes the clutch unit 43 to disengage and allows the jack shaft [4 to rotate independently of unit D while air bleeding from cylinder 52 of the power unit reduces the pressure in this unit and allows the air pressure in cylinder 66 of the return unit to force piston 61 therein downwardly which in turn returns sprocket and piston 63 of the power unit to their initial positions.

While we have disclosed a specific embodiment of the present invention, it will be apparent to a workman skilled in the art that various changes in the size and shapes of the several parts may be made without departing from the scope of the invention.

Having fully disclosed and illustrated the present invention, what we desire to claim as new and useful and to secure by Letters Patent is:

A device for giving limited angular rotation to a first shaft comprising, in combination, a second shaft concentric with the first shaft, a compressed air operated friction clutch releasably connecting the first and second shafts, an overriding clutch mounted on a second shaft, 2. sprocket mechanically connected with one element of said overriding clutch, a base member, a drive chain engaging with the teeth of the sprocket, a power unit and a return unit each having a cylinder as one element and a piston with piston rod attached thereto slidably arranged in the cylinder as another element, one element of each unit being secured to said base member and the other elements of said units being secured to opposite ends of said drive chain, the piston of said return unit being of substantially less area than the piston of said power unit, a first compressed air inlet line controlled by a first bleeder-type valve with compressed air control means connected to said compressed air operated friction clutch, a second compressed air line controlled by a second bleeder-type valve with compressed air control means to the cylinder of said power unit and a third compressed air line controlled by a third bleeder-type valve connected through a first branch to the compressed air control means of said first bleeder-type valve and through a second branch provided with a time delay unit to the compressed air control means of said second bleeder-type valve and a fourth compressed air inlet line connected to the cylinder of the return unit. w

ROBERT R. CROOKSTON. ARTHUR L. SELJOS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,106,930 Desmond Aug. 11, 1914 1,142,889 Knapp June 15, 1915 1,476,703 Forman Dec. 11, 1923 FOREIGN PATENTS Number Country Date 15,467 Great Britain July "I, 1906 $16,567 .Germany Oct. 8, 1899 

